1. Field of the Invention
The present invention relates to an ink cartridge for use as an ink supply source in an ink recording apparatus such as an ink jet printer or the like and, in particular, an ink cartridge having a waste ink absorbing function.
2. Description of the Related Prior Art
As an ink supply mechanism for use in an ink jet printer, there is conventionally known an ink supply mechanism structured such that an ink supply needle is previously disposed in an ink cartridge mounting portion formed in the ink jet printer, and, if an ink cartridge is mounted in such a manner that the ink supply needle can be inserted into an ink take-out port formed in the ink cartridge, then ink stored within the ink cartridge can be supplied to an ink jet head provided in the ink jet printer.
This type of ink cartridge for use in an ink jet printer is disclosed, for example, in Japanese Patent Publication No. 5-162333 of Heisei. In particular, in the ink tank cartridge disclosed in the present patent publication, as shown in FIG. 1 of the specification thereof, an ink bag and an ink absorbing member are stored within a rectangular-shaped inside space to be defined by upper and lower box bodies which cooperate together in forming the ink cartridge. The ink absorbing member is used to absorb the ink that leaks out from an ink guide needle (ink supply needle) which is inserted into the ink cartridge, thereby preventing such ink from leaking externally of the ink cartridge.
Also, as an ink cartridge having a waste ink absorbing function, there is known an ink cartridge which is disclosed in Japanese Patent Publication No. 63-116833 of Showa filed by the present applicant. That is, the ink vessel (ink cartridge) disclosed in the present patent publication is structured such that a space formed in the interior portion of a case for the ink cartridge is divided into two sections by a middle cover; in particular, an ink storage bag is stored in one of the two divided sections, whereas a waste ink absorbing member is stored in the other. The space section, in which the waste ink is stored, is defined by the case, middle cover, and an upper cover which is mounted on the case, so that the present space section provides a hermetically closed space or an airtight space. Or, the present space section is defined by a case which is divided to two sections, and a middle cover, so that the present space section provides a hermetically closed space. Here, in order to connect the plastics-made case and upper cover, or to connect together the two divided sections of the plastics-made case, there is employed an ultrasonic sealing method.
However, in the former structure, that is, in the ink cartridge disclosed in Japanese Patent Publication No. 5-162333 of Heisei, there is a fear that the waste ink absorbed by the ink absorbing member can leak out through the connected portions between the upper and lower box bodies. On the other hand, in the latter, that is, in the ink cartridge of a type that is disclosed in Japanese Patent Publication No. 63-116833 of Showa, the space, in which the ink absorbing member is stored, is substantially an airtight space because the connected portions of the members are sealed using ultrasonic waves and, therefore, there is no fear that the ink can leak. However, in the latter, there are still left the following problems that must be solved.
That is, firstly, generally, the ink cartridge is recycled. To recycle the ink cartridge, it is necessary to execute an operation in which the case for the ink cartridge is easily opened, the ink bag and ink absorbing member are replaced with new ones and, after then, the case is closed again. It is desirable to be able to carry out such operation simply and economically. However, as described above, in the structure in which the two cases, or the case and upper cover are connected together by an ultrasonic sealing method, when replacing the ink bag and ink absorbing member, the case and upper cover cannot be opened simply. Also, when the case and upper cover are opened once, in many cases, the welded portions of the two cases, or the welded portions of the case and upper cover can be damaged, which makes it impossible to recycle the ink cartridge; that is, the ink cartridge having such structure must be wasted and thus use of such ink cartridge is not economical. Further, there is another problem that to execute the ultrasonic sealing operation requires a large-scale installation.
Secondly, to provide a partition plate such as the middle cover or the like for dividing the interior portion of the ink cartridge case is not desirable from the point of view of reducing the weight and size of the ink cartridge.
Thirdly, generally, if the ink absorbing member absorbs ink, then it will expand in volume by an amount equivalent to the ink absorbed. For this reason, it is necessary that the ink absorbing member portion of the ink cartridge has been previously formed with such room as corresponds to the expansion of the ink absorbing member, which makes it necessary to increase the thickness of the ink cartridge by an amount equivalent to such room. However, this is not desirable from the point of view of reducing the size of the ink cartridge.
Fourthly, in some of the ink cartridges that have been used and collected for recycling, waste ink is little collected in the ink absorbing members thereof. However, even in such cases, conventionally, if the waste ink absorbing members thereof are contaminated with waste ink to any degree, the ink absorbing members are replaced with new ones. Therefore, even the waste ink absorbing member, the most part of which has not absorbed waste ink and thus is still capable of absorbing the waste ink, is taken out from the ink cartridge and is wasted as it is.